Understanding the Malnutrition Universal Screening Tool (MUST)
The Malnutrition Universal Screening Tool, or MUST, is a quick and straightforward screening tool designed to identify adults who are malnourished, at risk of malnutrition, or obese. It is widely used in various healthcare settings, including hospitals, care homes, and community clinics. By following a simple, five-step algorithm, healthcare workers can quickly assess a patient's nutritional status and formulate an appropriate care plan. This proactive approach is crucial for early intervention, as malnutrition can significantly impact a person's health, recovery time, and overall quality of life.
The Five-Step MUST Assessment Process
The MUST assessment is a structured process that combines clinical measurements and information about a patient's health to arrive at an overall risk score.
Step 1: Calculate the Body Mass Index (BMI) Score
The first step involves measuring or calculating the patient's BMI. BMI is determined by dividing a person’s weight in kilograms by the square of their height in meters ($$BMI = kg/m^2$$). Measurements should be as accurate as possible, using a height stick and calibrated weighing scales. If direct measurement is not feasible, alternative methods like using ulna length or a reliable self-reported weight can be used.
Scoring for BMI is as follows:
- BMI > 20 ($$> 30$$ obese): Score 0
- BMI 18.5–20: Score 1
- BMI < 18.5: Score 2
Step 2: Determine the Unplanned Weight Loss Score
Next, the assessor evaluates the percentage of unplanned weight loss over the past 3 to 6 months. This information can be gathered from patient records or by asking the patient or their caregivers. Evidence like loose-fitting clothes or jewellery can also serve as an indicator.
Scoring for weight loss is:
- Unplanned weight loss < 5%: Score 0
- Unplanned weight loss 5–10%: Score 1
- Unplanned weight loss > 10%: Score 2
Step 3: Assess the Acute Disease Effect
This step adds a score for the acute disease effect. A patient receives a score of 2 if they are acutely ill and there has been, or is likely to be, no nutritional intake for more than five consecutive days. This is a critical factor, as acute illness can rapidly increase the risk of malnutrition.
Step 4: Calculate the Overall Malnutrition Risk Score
The scores from the first three steps are added together to determine the overall risk category.
- Total score of 0 = Low Risk
- Total score of 1 = Medium Risk
- Total score of 2 or more = High Risk
This total score provides a clear, quantitative measure of the patient's nutritional status.
Step 5: Implement Management Guidelines
The final step uses the overall risk score to inform a specific management plan. The required actions vary by risk level and clinical setting, with more intensive intervention for high-risk patients.
Example Management Guidelines by Risk Category
| Risk Category | Management Action | Re-screening Frequency | Target Patient Group |
|---|---|---|---|
| Low Risk (Score 0) | Routine clinical care. Ensure ongoing monitoring of nutritional intake. | Monthly (Care Homes), Annually (Community), Weekly (Hospital) | Adults in stable health conditions |
| Medium Risk (Score 1) | Observe and document dietary intake for 3 days. Implement nutritional support if intake is inadequate. | Monthly (Care Homes), Every 2-3 Months (Community), Weekly (Hospital) | Adults with some risk factors, requiring closer monitoring |
| High Risk (Score 2 or more) | Immediately refer to a dietitian or nutritional support team. Initiate nutritional support following local policy. | Weekly (Hospital), Monthly (Care Homes/Community) | Adults with significant malnutrition risk needing immediate intervention |
For more detailed guidance and resources, you can consult the BAPEN website, the developer of the MUST tool The 'MUST' Explanatory Booklet.
Important Considerations and Alternative Measurements
In some cases, a patient's weight or height cannot be accurately measured due to physical limitations, fluid disturbances (oedema), or amputations. For these situations, healthcare professionals can use alternative anthropometric measurements, such as mid-upper arm circumference (MUAC), or rely on clinical judgement and subjective criteria. Subjective criteria might include observing visible wasting or changes in clothing fit.
Conclusion
The MUST assessment is a vital, systematic tool for healthcare professionals to screen, assess, and manage malnutrition risk in adult patients. Its five-step algorithm—covering BMI, weight loss, and acute disease effect—provides a standardized, evidence-based approach to identifying nutritional issues early. By categorizing patients into low, medium, or high-risk groups, the MUST tool ensures that appropriate, timely interventions are implemented. This not only helps mitigate the adverse health effects of malnutrition but also optimizes patient care and outcomes across various settings. Consistent use of the MUST assessment is a key component of comprehensive and quality nutritional care.
